Adjustable dampening for planter row unit

ABSTRACT

A row unit has a frame with an upper portion and a lower portion. The upper portion has a parallel linkage and the lower portion is coupled to plural gauge wheels. A first sensor is configured to provide an output signal and a controllable device is coupled to the upper portion and configured to provide an adjustable down force. A dampening device is coupled to the upper portion and configured to provide adjustable dampening of the row unit based on the output signal.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.62/353,590 filed Jun. 23, 2016, which is hereby incorporated byreference in its entirety.

BACKGROUND Technical Field

The present disclosure is generally related to agricultural equipment,and more particularly, agricultural equipment for seeding.

Description of Related Art

Row crop planters are used to seed fields. Field terrains differ intheir topology and/or surface conditions. Some surface conditions, suchas rough surfaces, may impact seed release from a row unit seedreservoir and/or seed placement in furrows created by the row units. Forinstance, rapid accelerations (e.g., jerky movements, or generally,rapid changes in direction) of the row units occurring as a result ofbeing towed across rough terrain may cause seed placement to be placedat varying depths, resulting in lower yield. Several different solutionsexist for planter down force control, including several that areclosed-loop controlled for changing conditions. These systems limit rowunit movement by using down pressure only. At least one agriculturalequipment manufacturer provides a passive dampening system on their rowunits to help mitigate the affects of rough terrain.

SUMMARY OF THE INVENTION

A row unit has a frame with an upper portion and a lower portion. Theupper portion has a parallel linkage and the lower portion is coupled toplural gauge wheels. A first sensor is configured to provide an outputsignal and a controllable device is coupled to the upper portion andconfigured to provide an adjustable down force. A dampening device iscoupled to the upper portion and configured to provide adjustabledampening of the row unit based on the output signal.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the disclosure can be better understood with referenceto the following drawings. The components in the drawings are notnecessarily to scale, emphasis instead being placed upon clearlyillustrating the principles of the present disclosure. Moreover, in thedrawings, like reference numerals designate corresponding partsthroughout the several views.

FIG. 1 is a schematic diagram that illustrates, in rear perspectiveview, a planter comprising a plurality of row units for which certainembodiments of a planter adjustable dampening system may be used.

FIG. 2 is a schematic diagram that illustrates, in rear elevation view,an air bag comprising an integrated magnetorheological fluid dampenercoupled to an upper portion of each of the row units of FIG. 1.

FIG. 3A is a block diagram that illustrates an embodiment of an examplecontrol system for a planter adjustable dampening system.

FIG. 3B is a block diagram that illustrates an embodiment of an examplecontroller for the control system of FIG. 3A.

FIG. 4 is a flow diagram that illustrates an embodiment of an exampleplanter adjustable dampening method.

DESCRIPTION OF EXAMPLE EMBODIMENTS

Certain embodiments of a planter adjustable dampening system and methodare disclosed that use different controls for down force and dampeningof row units of a planter. In one embodiment, a performance threshold isbased on acceptable seed placement based on movement of a row unit. Themovement may be measured based on sensor data, such as accelerometerdata or position data of a cylinder or other moveable mechanisms usedfor down force control. The planter adjustable dampening system monitorsthe accelerations of the row unit, and when the accelerations meet orexceed a predetermined threshold, a dampening action is implemented thatis separate from the down force controls, the dampening action used tocontrol the shock of abrupt row unit movement (accelerations, includinglurch or jerking motions) that may occur while traversing a field.

Digressing briefly, conventional planter systems use either down forcecontrol or passive dampening, but not both types of controls. By usingseparate control of down force and dampening, one benefit may be areduction in the change in seed trajectory inside a traditional seedtube and/or more consistent release of seed from a seed tube to thetrench (furrow).

Having summarized certain features of a planter adjustable dampeningsystem of the present disclosure, reference will now be made in detailto the description of the planter adjustable dampening system asillustrated in the drawings. While the planter adjustable dampeningsystem is described in connection with these drawings, there is nointent to limit the system to the embodiment or embodiments disclosedherein. Further, although the description identifies or describesspecifics of one or more embodiments, such specifics are not necessarilypart of every embodiment, nor are all various stated advantagesnecessarily associated with a single embodiment or all embodiments. Onthe contrary, the intent is to cover all alternatives, modifications andequivalents included within the spirit and scope of the disclosure asdefined by the appended claims. Further, it should be appreciated in thecontext of the present disclosure that the claims are not necessarilylimited to the particular embodiments set out in the description.

It is noted that reference herein to left and right and front and rearis from the perspective of an operator navigating a tractor or othertowing vehicle that tows a planter in a forward direction. Also,reference to down force refers to the force that is applied to a rowunit by an actuable device, such as an air bag, hydraulic or pneumaticactuator, etc. Reference to down force margin includes an amount ofadditional down force applied to a row unit that is beyond that requiredto achieve penetration (e.g., by furrow openers) to a desired plantingdepth, the additional weight carried by gauge wheels. The soil providesa resistance to the penetration. Thus, the sum of the weight of the rowunit and the down force, with the soil resistance subtracted from thesum, equates to a down force margin (e.g., target down force margin).Dampening refers to a reduction in rate of change in direction of rowunit movement, effectively reducing peak acceleration frequency and/oramplitude experienced by conventional row units operating over roughfield surfaces. Stated otherwise, in certain situations, the effects ofacceleration are a limiting factor to controlled seed placement, asopposed to downforce control or downforce margins. It should beappreciated by one having ordinary skill in the art, in the context ofthe present disclosure, that smoothing out the ride through dampeningcontrol is balanced with a reduction in down force margins.

FIG. 1 is a schematic diagram that illustrates a planter 10 comprising aplurality of row units 12 being towed by a towing vehicle 14 (e.g.,tractor), the planter 10 comprising an embodiment of a planteradjustable dampening system. For instance, a suitable row unit 12 may beembodied as a White Planters 8000 or 9000 Series row unit by AGCO,though others styles of row units and/or row units provided by othermanufacturers may be suitable hosts for certain embodiments of a planteradjustable dampening system, and hence are contemplated to be within thescope of the disclosure. The row units 12 of the planter 10 are coupledto a transverse draw bar 16 that is part of a frame or frames thatcouples to the towing vehicle 14. Though the planter 10 in FIG. 1 isdepicted with two reservoirs 18, one each for the left-two row units 12in FIG. 1, it should be appreciated by one having ordinary skill in theart that each row unit 12 will typically be equipped with a reservoir 18that holds seed to be extracted and disbursed into the field, and thatthe quantity of row units 12 may be different for certainimplementations (e.g., in some implementations, up to forty-eight (48)row units). Referring to the row unit 12 at the right in FIG. 1 that hasthe reservoir 18 removed, which more fully shows the row unit features,the row unit 12 comprises a frame 20 having an upper portion 22 and alower portion 24 comprising an equalizer arm. Also shown coupled to thelower portion 24 are gauge wheels 26 and closing wheels 28. Also coupledto the lower portion are furrow openers (obscured from view). The gaugewheels 26 are positioned slightly behind and immediately adjacent therespective furrow openers. As the gauge wheels 26, furrow openers, andclosing wheels 28 are of a known function and structure, the descriptionof the same is omitted here to avoid obfuscating the features of aplanter adjustable dampening system. The upper portion 22 comprises aparallel linkage 30, which is a linkage commonly used among row units ingeneral. The parallel linkage 30 permits up and down movement of the rowunit 12 relative to the draw bar 16. Also shown coupled to the upperportion 22 and the draw bar 16 is a control and dampening device 32,shown in close-up in FIG. 2. The control and dampening device 32comprises two devices integrated into a single package, including acontrollable device for adjustable control of the down force for the rowunit 12, and a dampening device for adjustable control of the dampeningrate of the row unit 12. The controllable device comprises an air bag(also known as air spring), though other types of actuable devices maybe used, including hydraulic actuators, springs, etc. The dampeningdevice comprises a magnetorheological (MR) fluid dampener, though insome embodiments, other types of dampening devices may be used,including those that vary the dampening rates by changing the viscosityof their fluid or vary the orifice characteristics. In some embodiments,the controllable device and the dampening device may be separatelypackaged units arranged proximal to each other and both coupled betweenthe upper portion 22/draw bar 16 and a lower frame member 34 of theparallel linkage 30. Hereinafter, the focus of the description for thecontrol and dampening device 32 is based on the embodiment using anintegrated package except where noted below, with the understanding thatthe description that follows is similarly applicable to the separatelypackaged embodiment. With continued reference to FIGS. 1-2, thecontrollable device is adjustable (e.g., via an air valve or solenoidthat is operably connected to a controller), enabling an increase ordecrease in down force. For instance, an air source, such as acompressor, provides a supply of air to the controllable device via theair valve, the air valve opening and closing to control the flow of airto the controllable device. The controllable device acts between thedraw bar 16 and the parallel linkage 30 to apply a down force on the rowunit 12. The down force applied by the controllable device provides asufficient amount of force to enable insertion of furrow openers (e.g.,double disc furrow or trench openers, obscured from view in FIG. 1) intothe soil to form a furrow or trench of desired depth. Though thedescription above discloses the use of air, other fluids may be used.The dampening device, as indicated above, comprises an (MR) fluiddampener, though in some embodiments, dampening devices that employelectrophoretic fluids (EP), electrorheological fluids (ER), orhydraulic fluids (e.g., semi-active electromechanical) may be used. Inthe description that follows, a short description of an exampledampening device that operates according to magnetorheological fluidcontrol is described with the understanding that other mechanisms (e.g.,ER, EP, adjustable hydraulic, etc.) known in the art may be used for thedampening function.

The MR fluid dampener (also known as an MR fluid damper), as is known,comprises in one design version a cylindrical hollow body which ispartially closed at one end and fully closed at the other end. A slenderrigid piston rod is slidably and sealingly received in an apertureformed within a bushing and sealed by a seal, both of which aresupported within end caps at each end. The MR fluid dampener includes anaccumulator comprised of a partition, such as a diaphragm, and a gaschamber. The accumulator functions to accommodate the fluid displacedwhen the piston rod enters into an internal chamber. A fill valve isused to appropriately pressurize the chamber. Other types ofaccumulators may be used, as are known to those of ordinary skill in theart. The piston assembly separates the internal chamber into first andsecond fluid chambers. The piston assembly preferably includes anaxially extending annular passage through which the controllable fluid,such as an MR fluid may flow. The piston assembly comprises a wear bandor wear bands manufactured from an appropriate friction reducingmaterial and of the appropriate diameter to cause the piston assembly toact as a plunger to force MR fluid between the chambers as a consequenceof row unit (acceleration) movement. A magnetic field is generated bysupplying a control signal to leads of the MR fluid dampener, whichelectrically interconnect to a circumferentially wound coil supportedwithin the piston assembly. The magnetic field is directed by pole toact across the MR fluid contained within the annular passage, whichcauses a rheology change (a thickening or apparent viscosity change)which restricts flow of the MR fluid through the passage. If the currentis high enough, the flow is stopped altogether, thus substantiallylocking up the MR fluid dampener and resultantly locking up andpreventing further acceleration motion. Notably, the current ispreferably rapidly switched from a high current value to a low currentvalue (depending upon the sensor inputs) to accomplish real time changesin dampening. As indicated above, though described above in the contextof a particular piston design using MR fluids, other pistonconfigurations and/or fluids may be used, including Electrorheological(ER) fluids or Electrophoretic (EP) fluids or hydraulic (e.g.,semi-active configurations) fluids for use in respective types ofwell-known dampener configurations.

Attention is now directed to FIG. 3A, which illustrates an embodiment ofan example control system 36 for a planter adjustable dampening system.One having ordinary skill in the art should appreciate in the context ofthe present disclosure that the example control system 36 is merelyillustrative, and that some embodiments of control systems may comprisefewer or additional components, and/or some of the functionalityassociated with the various components depicted in FIG. 3A may becombined, or further distributed among additional components, in someembodiments. For instance, in one embodiment, the control system 36 isdistributed among the planter 10 (including at one or more of the rowunits 12) and the towing vehicle. In some embodiments, the controlsystem 36 is hosted entirely by the planter 10. In some embodiments, thecontrol system 36 is distributed among the planter 10 and a remotecomputing device (e.g., in communication with components of the controlsystem 36 via telemetry or radio frequency communications), and in someembodiments, the control system 36 is distributed among the towingvehicle, the planter 10, and a remote computing device. It should beappreciated by one having ordinary skill in the art that featurescorresponding to the various embodiments of a control system 36described herein are interchangeably used with functionality of aplanter adjustable dampening system. For purposes of brevity, attentionis focused on an embodiment where the control system 36 is distributedamong the planter 10 and a towing vehicle, with the understanding thatother configurations may be used in some embodiments. The control system36 comprises one or more controllers, such as controller 38, pluralsensors 40, 42, plural dampening devices 44, plural controllable devices46, and user interfaces 48, all coupled over a network 50, such as acontroller area network (CAN), though not limited to a CAN network or asingle network. In one embodiment, the network 50 may comprise a wirednetwork (e.g., twisted pair, copper, etc.), a wireless network (e.g.,based on IEEE 802.11, Bluetooth, Near Field Communications (NFC), etc.),or a combination of a wired and wireless network. It is noted that theremay be plural controllers (an additional one shown in phantom (dashedline) and coupled to the network 50). For instance, the controller 38may be dedicated to control of the dampening devices 44, and the othercontroller may be dedicated to control of the controllable devices 46.For purposes of brevity, the following discussion describes thecontroller 38 as providing control for both the dampening devices 44 andthe controllable devices 46, with the understanding that in someembodiments, respective controllers may handle respective down force anddampening functions. The controller 38 is explained further below. Inone embodiment, the sensors 40 comprise accelerometers, with eachaccelerometer coupled to the frame 20 (FIG. 1) of a particular row unit12 (FIG. 1) and used to measure acceleration of the corresponding (e.g.,host) row unit 12. In one embodiment, the sensors 40 comprise positionsensors. For instance, for each row unit 12, the position sensor may bepositioned internally to the controllable device (e.g., within acylinder or housing of the controllable device) and/or externally (e.g.,measuring the positional change of an extending unit, such as a piston)to the controllable device. In some embodiments, a mix of types ofsensors may be deployed. In some embodiments, other types of sensors maybe used, such as acoustic, optical, magnetic, etc. The sensors 42 arecoupled to the frame 20 of a particular row unit 12, and used to measurethe soil resistance for purposes of providing feedback of down forcerequired. For instance, the sensors 42 may comprise a load cell, as isknown in the art. In some embodiments, other sensors 42 may be used,such as a global navigation satellite system (GNSS) receiver, which incooperation with a depth or field map, matches a particular fieldcoordinate (and hence soil hardness) with the required down force. Insome embodiments, hardness of the soil may be supplemented or replacedwith other parameters, such as bulk density, soil series type, and/orresidue levels. In some embodiments, the sensors 40, 42 may comprise allor of any combination of these types of sensors, or a subset of them insome embodiments.

The user interfaces 48 may include an FNR handle, a keyboard/pad and/ormouse, a display device (e.g., tough-type display, liquid crystal diode(LCD), plasma-based, etc.), and/or other input and output devices (e.g.,a microphone for audible input, a speaker for audible output, in someembodiments). In other words, the user interfaces 48 may enable anoperator to input the level of ride smoothness and/or down force. Basedon the input, the controller 38 causes adjustment of the dampeningdevices 44 and/or the controllable devices 46 to effect the desireddampening or down force, respectively. Adjustments to either the downforce or dampening while the planter 10 (FIG. 1) is operating in thefield may be communicated to the user interfaces 48 (e.g., displayscreen, headset, etc.) to inform the operator that such changes havetaken place, and in some embodiments, to give the operator anopportunity to reject or accept the impending changes (or acknowledgethe changes in some embodiments). The user interfaces 48 may providefeedback of adjustments visually, audibly, and/or via tactilemechanisms. In some embodiments, the user interfaces 48 may afford theoperator control of dampening and/or down force. These and/or othermechanisms of operator control and/or feedback of down force anddampening may be used, and hence are contemplated to be within the scopeof the disclosure.

In one embodiment, the dampening devices 44 are each embodied as thedampening device of the control and dampening device 32. In oneembodiment, the dampening devices 44 comprise MR fluid dampeningdevices, though other types of dampening devices may be used as setforth previously.

In one embodiment, the controllable devices 46 are each embodied as thecontrollable device of the control and dampening device 32. In oneembodiment, the controllable devices comprise air bags (air springs),though other types of controllable devices may be used as set forthpreviously. As indicated previously, the controllable devices 46, whenembodied as air bags, may be supplied by a source of air from acompressor and controlled using an air valve or other mechanism ofcontrol known in the art. It is noted that, although the dampeningdevices 44 and the controllable devices 46 are depicted separately inFIG. 3A, the separation corresponds to a logical separation (e.g.,manner of control), and that in some embodiments, the devices 44, 46 foreach row unit 12 may be separately packaged and adjacent to each otherand in some embodiments, the devices 44, 46 for each row unit 12 may beprovided as a single package (as represented by the dashed box outliningthe combination of devices 44, 46).

Referring to FIG. 3B, shown is an embodiment of the example controller38, which comprises a computer architecture. It should be appreciated byone having ordinary skill in the art that the controller 38 depicted inFIG. 3B is one example illustration, and that in some embodiments,fewer, greater, and/or different components may be used. Also, it shouldbe appreciated by one having ordinary skill in the art that certainwell-known components of computer systems are omitted here to avoidobfuscating relevant features of the controller 38. In one embodiment,the controller 38 comprises one or more processing units 52,input/output (I/O) interface(s) 54, and memory 56, all coupled to one ormore data busses, such as data bus 58. The memory 56 may include any oneor a combination of volatile memory elements (e.g., random-access memoryRAM, such as DRAM, SRAM, and SDRAM, etc.) and nonvolatile memoryelements (e.g., ROM, Flash, solid state, EPROM, EEPROM, hard drive,CDROM, etc.). The memory 56 may store a native operating system, one ormore native applications, emulation systems, or emulated applicationsfor any of a variety of operating systems and/or emulated hardwareplatforms, emulated operating systems, etc. In the embodiment depictedin FIG. 3B, the memory 56 comprises an operating system 60 andapplication software 62. The application software 62 comprises downforce adjust software 64 and dampening adjust software 66. Additionalsoftware may be used in some embodiments, including a depth/field map,graphical user interface (GUI) software, browser software,communications software, etc. It should be appreciated that in someembodiments, additional or fewer software modules (e.g., combinedfunctionality) may be employed in the memory 56 or additional memory. Insome embodiments, a separate storage device may be coupled to the databus 58 or coupled via the I/O interfaces 54, such as a persistent memory(e.g., optical, magnetic, and/or semiconductor memory and associateddrives).

With continued reference to FIGS. 1-3A, and referring also to FIG. 3B,the down force adjust software 64 computes or determines a down forcemargin (e.g., for each row unit 12) based on the weight of each row unit12, the down force (as predetermined according to a default value,manually entered by the operator, and/or as determined by the down forceadjust software based on sensor input or historical values for the samefield location, such as from a data structure or based on field or depthmap data), and the soil resistance (e.g., as entered by the operator,such as via selection from a presented list matching the soil resistanceto a soil type for the field to be traversed, via sensor input, and/orvia field or depth map data or historical data). In one embodiment,changes in soil hardness may be detected by the sensor 42 andcommunicated to the down force adjust software 64, which in turn sends asignal to the controllable devices 46 to adjust the down force on therow units 12.

The dampening adjust software 66 receives a signal from sensors 40,which indicates a parameter (e.g., a position of a moving member of thecontrollable device 46, rate of change in direction and/or accelerationof the row unit 12, etc.). The dampening adjust software 66 compares thevalue of the parameter to a threshold value that is programmed into, oraccessed by, the application software 62. The threshold value mayassociate the parameter with the commencement or impending commencementof undesirable seed placement (e.g., impending in the sense that theremay be a built-in tolerance level that considers reaction time by thecontrol system 36 to jerking or lurching actions of the row unit 12). Inother words, if the value of the sensed parameter meets or exceeds thethreshold value, seed placement is at risk of being improper orundesirable. In some embodiments, plural thresholds may be used andstored in a data structure, each threshold based on crop conditions,soil conditions, historical data, weather, moisture, etc. If thethreshold value is met or exceeded, the application software 62 causesactuation of the dampening devices 44 to adjust the dampening rate toensure a smooth ride and mitigate the jerky movements that would comeabout from rough terrain.

Execution of the application software 62, including the down forceadjust software 64 and dampening adjust software 66, are implemented bythe processing unit 52 under the auspices of the operating system 60. Insome embodiments, the operating system 60 may be omitted and a morerudimentary manner of control implemented. The processing unit 52 may beembodied as a custom-made or commercially available processor, a centralprocessing unit (CPU) or an auxiliary processor among severalprocessors, a semiconductor based microprocessor (in the form of amicrochip), a macroprocessor, one or more application specificintegrated circuits (ASICs), a plurality of suitably configured digitallogic gates, and/or other well-known electrical configurationscomprising discrete elements both individually and in variouscombinations to coordinate the overall operation of the controller 38.

The I/O interfaces 54 provide one or more interfaces to the network 50,as well as interfaces to one or more user interfaces. For instance, theI/O interfaces 50 receive wired or wireless signals from the sensors 40,42, and provides control signals to the dampening devices 44 andcontrollable devices 46. The I/O interfaces 54 may also be coupled toone or more user interfaces or other devices to enable control ofnavigation and/or other machine functions. In some embodiments, the userinterfaces 48 may comprise a headset-type display that is coupled to theI/O interfaces 54.

Note that the controller 38 and/or the control system 36 may compriseadditional functionality, such as a cellular modem and browser softwarefor accessing devices communicating with a wide area network and/orradio frequency modem for communications with devices located externalto the planter 10 and/or the towing vehicle, as well as machine controlsoftware for enabling planting control of the planter 10.

When certain embodiments of the controller 38 are implemented at leastin part in logic configured as software/firmware, as depicted in FIG.3B, it should be noted that the logic can be stored on a variety ofnon-transitory computer-readable medium for use by, or in connectionwith, a variety of computer-related systems or methods. In the contextof this document, a computer-readable medium may comprise an electronic,magnetic, optical, or other physical device or apparatus that maycontain or store a computer program for use by or in connection with acomputer-related system or method. The logic may be embedded in avariety of computer-readable mediums for use by, or in connection with,an instruction execution system, apparatus, or device, such as acomputer-based system, processor-containing system, or other system thatcan fetch the instructions from the instruction execution system,apparatus, or device and execute the instructions.

When certain embodiment of the controller 38 are implemented at least inpart in logic configured as hardware, such functionality may beimplemented with any or a combination of the following technologies,which are all well-known in the art: a discrete logic circuit(s) havinglogic gates for implementing logic functions upon data signals, anapplication specific integrated circuit (ASIC) having appropriatecombinational logic gates, a programmable gate array(s) (PGA), a fieldprogrammable gate array (FPGA), etc.

In view of the above description, it should be appreciated that oneembodiment of a method for operating a row unit having a framecomprising an upper portion and a lower portion, the upper portioncomprising a parallel linkage, the lower portion coupled to plural gaugewheels, denoted in FIG. 4 as method 68, comprises sensing a parameterand providing an output signal (70); providing an adjustable down force(72); and providing adjustable dampening of the row unit based on theoutput signal (74).

Any process descriptions or blocks in flow diagrams should be understoodas representing modules, segments, or portions of code which include oneor more executable instructions for implementing specific logicalfunctions or steps in the process, and alternate implementations areincluded within the scope of the embodiments in which functions may beexecuted out of order from that shown or discussed, includingsubstantially concurrently or in reverse order, depending on thefunctionality involved, as would be understood by those reasonablyskilled in the art of the present disclosure.

It should be emphasized that the above-described embodiments of thepresent invention are merely possible examples of implementations,merely set forth for a clear understanding of the principles of thedisclosure. Many variations and modifications may be made to theabove-described embodiment(s) of the disclosure without departingsubstantially from the spirit and principles of the disclosure. Forinstance, although described as using a dampening device per row unit,some embodiments may use a dampening device for plural row units. Allsuch modifications and variations are intended to be included hereinwithin the scope of this disclosure and protected by the followingclaims.

At least the following is claimed:
 1. A row unit, comprising: a framecomprising an upper portion and a lower portion, the upper portioncomprising a parallel linkage, the lower portion coupled to plural gaugewheels; a first sensor configured to provide an output signal, whereinthe first sensor comprises an accelerometer; a controllable devicecoupled to the upper portion and configured to provide an adjustabledown force; and a dampening device coupled to the upper portion andconfigured to provide adjustable dampening of the row unit based on theoutput signal.
 2. The row unit of claim 1, wherein the dampening devicecomprises a magnetorheological fluid dampener, an electrorheologicalfluid dampener, an electrophoretic fluid dampener, or an adjustablehydraulic fluid dampener.
 3. The row unit of claim 1, wherein thedampening device is disposed adjacent to and separate from thecontrollable device.
 4. The row unit of claim 1, wherein the dampeningdevice is integrally disposed within the controllable device.
 5. The rowunit of claim 1, wherein the controllable device comprises an air bag.6. The row unit of claim 1, further comprising a second sensor, whereinbased on a signal from the second sensor, the controllable deviceadjusts the down force.
 7. The row unit of claim 6, wherein the secondsensor comprises a load cell.
 8. The row unit of claim 1, wherein thedampening device is configured to adjust a dampening rate of the rowunit based on the output signal meeting or exceeding a threshold value.9. The row unit of claim 8, wherein the threshold value comprises athreshold acceleration of the row unit or a threshold change in positionof a cylinder of the controllable device.
 10. A planter adjustabledampening system, comprising: a draw bar; a plurality of row units,wherein each of the row units comprises: a frame comprising an upperportion and a lower portion, the upper portion comprising a parallellinkage coupled to the draw bar, the lower portion coupled to pluralgauge wheels; a sensor configured to provide an output signal; acontrollable device coupled between the draw bar and a lower framemember of the parallel linkage and configured to provide an adjustabledown force; and a dampening device coupled between the draw bar and thelower frame member of the parallel linkage and configured to provideadjustable dampening based on the output signal; and a controllerconfigured to: receive the output signal; compare the output signal to athreshold value; responsive to the output signal meeting or exceedingthe threshold value, signal the dampening device to adjust a dampeningrate; wherein the threshold value is based on an acceleration or acylinder position of the controllable device where corresponding seedplacement from the row unit is undesired.
 11. The planter adjustabledampening system of claim 10, further comprising an additionalcontroller and an additional sensor associated with the controllabledevice, wherein based on output from the additional sensor, theadditional controller is configured to signal the controllable device toadjust the down force.
 12. The planter adjustable dampening system ofclaim 10, further comprising an additional sensor, wherein based onoutput from the additional sensor, the controller is configured tosignal the controllable device to adjust the down force.
 13. The planteradjustable dampening system of claim 10, wherein the dampening devicecomprises a magnetorheological fluid dampener, an electrorheologicalfluid dampener, an electrophoretic fluid dampener, or an adjustablehydraulic fluid dampener.
 14. The planter adjustable dampening system ofclaim 10, wherein the sensor comprises either an accelerometer or aposition sensor coupled to the controllable device.
 15. The planteradjustable dampening system of claim 10, wherein the controllable deviceand the dampening device are packaged in a single package.